Alvarez's proof: grace in the intellect is external to the will
Thesis XXXV. He proves it as follows: 'For salvation it is necessary not only that the intellect know what to do and what to avoid, but also that the will will to embrace good and avoid evil, and to love God above all things. But by rousing grace received in the intellect alone, the will cannot will anything that leads to salvation, nor love God above all things.
'For grace present in the intellect is external to the will, and so it does not give the will a sufficient principle for performing works of piety.' He concludes that grace received only in the intellect is not grace sufficient for salvation. Epitome de auxiliis, book 3, chapter 16.
Latin
XXXV. Hoc autem inde probat quod, Ad salutem non solum est necessarium, ut intellectus cognoscat quid faciendum sit, quidve fugiendum; sed etiam oportet quod voluntas velit bonum amplecti, & malum fugere, ac Deum super omnia diligere: sed per gratiam excitantem in solo intellectu receptam, non potest voluntas aliquid velle, quod sit ad salutem conducens, nec Deum super omnia diligere: Quia gratia existens in intellectu, extrinseca est voluntati; ac per consequens, non tribuit illi sufficiens principium, quo possit opera pietatis exercere. Unde concludit, solam gratiam in intellectu receptam, non esse gratiam sufficientem ad salutem. Epit. de Auxiliis lib. 3. cap. 16.